(There are many hadiths
to support the followings, but only few have been quoted).

Offering five daily farj prayers in congregation is
compulsory:

Narrated Ibn 'Umar: Allah's Apostle said: Islam is based on
(the following) five (principles): 1. To testify that none has the right to be
worshipped but Allah and Muhammad is Allah's Apostle. 2. To offer the (compulsory
congregational) prayers dutifully and perfectly. 3. To pay Zakat (i.e.
obligatory charity) . 4. To perform Hajj. (i.e. Pilgrimage to Mecca) 5. To
observe fast during the month of Ramadan. (Bukhari
Book #2,
Hadith #7).

Narrated Abu Huraira: Allah's Apostle said, "By Him in
Whose Hand my soul is I was about to order for collecting fire-wood (fuel) and
then order Someone to pronounce the Adhan for the prayer and then order someone
to lead the prayer then I would go from behind and burn the houses of men who
did not present themselves for the (compulsory congregational) prayer. By Him,
in Whose Hands my soul is, if anyone of them had known that he would get a bone
covered with good meat or two (small) pieces of meat present in between two
ribs, he would have turned up for the 'Isha' prayer.' (Bukhari Book #11,
Hadith #617).

Narrated Abu Huraira: The Prophet (p.b.u.h) said,
"Seven people will be shaded by Allah under His shade on the day when
there will be no shade except His. They are: (1) a just ruler; (2) a young man
who has been brought up in the worship of Allah, (i.e. worship Allah (Alone)
sincerely from his childhood), (3) a man whose heart is attached to the mosque
(who offers the five compulsory congregational prayers in the mosque); (4) two
persons who love each other only for Allah's sake and they meet and part in
Allah's cause only; (5) a man who refuses the call of a charming woman of noble
birth for an illegal sexual intercourse with her and says: I am afraid of
Allah; (6) a person who practices charity so secretly that his left hand does
not know what his right hand has given (i.e. nobody knows how much he has given
in charity). (7) a person who remembers Allah in seclusion and his eyes get
flooded with tears." (Bukhari Book #24,
Hadith #504).

Narrated Muhammad bin Sirin: On a rainy day Ibn Abbas said
to his Muadh-dhin, "After saying, 'Ash-hadu anna Muhammadan Rasulullah' (I
testify that Muhammad is Allah's Apostle), do not say 'Haiya 'Alas-Salat' (come
for the prayer) but say 'Pray in your houses'." (The man did so). But the
people disliked it. Ibn Abbas said, "It was done by one who was much
better than I (i.e. the Prophet (p.b.u.h) ). No doubt, the Jumua prayer is compulsory
but I dislike to put you to task by bringing you out walking in mud and
slush." (Bukhari Book #13,
Hadith #24).

Narrated Anas bin Malik: Once the Iqama was pronounced and
Allah's Apostle faced us and said, "Straighten your rows and stand closer
together, for I see you from behind my back.' (Bukhari
Book #11,
Hadith #687).

Narrated Anas bin Malik: The Prophet said, "Straighten your
rows as the Straightening of rows is essential for a perfect and correct prayer.
" (Bukhari Book #11,
Hadith #690).

Narrated Anas bin Malik: The Prophet said, "Straighten your
rows for I see you from behind my back." Anas added, "Everyone of us
used to put his shoulder with the shoulder of his companion and his foot with
the foot of his companion." (Bukhari Book #11,
Hadith #692).

The oldest among the congregation
should lead the prayer:

Narrated Malik bin Huwairth: I came to the Prophet with some
men from my tribe and stayed with him for twenty nights. He was kind and
merciful to us. When he realized our longing for our families, he said to us,
"Go back and stay with your families and teach them the religion, and offer
the prayer and one of you should pronounce the Adhan for the prayer when its
time is due and the oldest one amongst you should lead the prayer." (Book #11,
Hadith #601).

Narrated Malik bin Huwairth: Two men came to the Prophet
with the intention of a journey. The Prophet said, "When (both of) you set
out, pronounce Adhan and then Iqama and the oldest of you should lead the
prayer." (Book #11,
Hadith #603).

Narrated Abu Huraira: The Prophet said, "The Imam is
(appointed) to be followed. So do not differ from him, bow when he bows, and
say, "Rabbana-lakal hamd" if he says "Sami'a-l-lahu Liman hamida";
and if he prostrates, prostrate (after him), and if he prays sitting, pray sitting
all together, and Straighten the rows for the prayer, as the Straightening of
the rows is amongst those things which make your prayer a correct and perfect
one. (See Hadith No. 657). (Bukhari Book #11,
Hadith #689).

Joining a congregation prayer with
calmness:

Narrated 'Abdullah bin Abi Qatada: My father said,
"While we were praying with the Prophet he heard the noise of some people.
After the prayer he said, 'What is the matter?' They replied 'We were hurrying
for the prayer.' He said, 'Do not make haste for the prayer, and whenever you
come for the prayer, you should come with calmness, and pray whatever you get
(with the people) and complete the rest which you have missed." (Bukhari Book #11,
Hadith #608).

Narrated Abu Huraira: The Prophet said, "When you hear
the Iqama, proceed to offer the prayer with calmness and solemnity and do not
make haste. And pray whatever you are able to pray and complete whatever you
have missed. (Bukahri Book #11,
Hadith #609).

Narrated 'Aisha: The Prophet said, "If supper is
served, and Iqama is pronounced one should start with the supper." (Bukhari Book #11,
Hadith #640).

Compulsory prayers and worships are
not to be missed:

Narrated Talha bin 'Ubaidullah: A man came to Allah's
Apostle asking him about Islam, Allah's Apostle said, "You have to offer
five compulsory prayers in a day and a night (24 hours)." The man asked,
"Is there any more compulsory prayers for me?" Allah's Apostle said,
"No, unless you like to offer Nawafil (i.e. optional prayers)."
Allah's Apostle then added, "You have to observe fasts during the month of
Ramadan." The man said, "Am I to fast any other days?' Allah's
Apostle said, "No, unless you wish to observe the optional fast
voluntarily." Then Allah's Apostle told him about the compulsory Zakat.
The man asked, "Do I have to give anything besides?" Allah's Apostle
said, "No, unless you wish to give in charity voluntarily." So, the
man departed saying, "By Allah I will neither do more nor less than
that." Allah's Apostle said, "If he has said the truth he will be
successful." (Bulhari Book #48,
Hadith #843).

Congressional (jamaat) prayers are to be shortened:

Narrated Anas: The Prophet used to pray a short prayer (in
congregation) but used to offer it in a perfect manner. (Bukhari Book #11,
Hadith #674).

Narrated Abu Mas'ud Al-Ansari: Once a man said to Allah's
Apostle "O Allah's Apostle! I may not attend the (compulsory
congregational) prayer because so and so (the Imam) prolongs the prayer when he
leads us for it. The narrator added: "I never saw the Prophet more furious
in giving advice than he was on that day. The Prophet said, "O people!
Some of you make others dislike good deeds (the prayers). So whoever leads the
people in prayer should shorten it because among them there are the sick the
weak and the needy (having some jobs to do)." (Bukhari
Book #3,
Hadith #90).

Narrated Abu Mas'ud: A man came to the Prophet and said
"I keep away from the morning prayer only because such and such person
prolongs the prayer when he leads us in it. The narrator added: I had never
seen Allah's Apostle more furious in giving advice than he was on that day. He
said, "O people! There are some among you who make others dislike good
deeds) cause the others to have aversion (to congregational prayers). Beware!
Whoever among you leads the people in prayer should not prolong it, because
among them there are the sick, the old, and the needy." (See Hadith No.
670, Vol 1) (Bukhari Book #73,
Hadith #131).

Benefits of saying “Amin” and “Allahumma
Rabbana laka-l-hamd”:

Narrated Abu Huraira: Allah's Apostle said, "Say amen'
when the Imam says "Ghair-il-maghdubi 'alaihim wala-ddal-lin; not the path
of those who earn Your Anger (such as Jews) nor of those who go astray (such as
Christians); all the past sins of the person whose saying (of Amin) coincides
with that of the angels, will be forgiven. (Bukhari
Book #12,
Hadith #749).

Narrated Abu Huraira: Allah's Apostle said, "If any one
of you says, "Amin" and the angels in the heavens say "Amin"
and the former coincides with the latter, all his past sins will be forgiven."
(Bukhari Book #12,
Hadith #748).

Narrated Abu Huraira: Allah's Apostle said, "When the
Imam says, "Sami' a-l-lahu Liman hamida," you should say, "Allahumma
Rabbana laka-l-hamd." And if the saying of any one of you coincides with
that of the angels, all his past sins will be forgiven." (Book #12,
Hadith #762).

Higher reward for standing on the
front rows in a congregation prayer:

Narrated Abu Huraira: Allah's Apostle said, "If the
people knew the reward for pronouncing the Adhan and for standing in the first
row (in congregational prayers) and found no other way to get that except by
drawing lots they would draw lots, and if they knew the reward of the Zuhr
prayer (in the early moments of its stated time) they would race for it (go
early) and if they knew the reward of 'Isha' and Fajr (morning) prayers in
congregation, they would come to offer them even if they had to crawl."
(Bukhari Book #11,
Hadith #589).

Ablution followed by two rakat prayer:

Narrated Humran: (the slave of 'Uthman) I saw 'Uthman bin 'Affan
asking for a tumbler of water (and when it was brought) he poured water over
his hands and washed them thrice and then put his right hand in the water
container and rinsed his mouth, washed his nose by putting water in it and then
blowing it out. then he washed his face and forearrlns up to the elbows thrice,
passed his wet hands over his head and washed his feet up to the ankles thrice.
Then he said, "Allah's Apostle said 'If anyone Performs ablution like that
of mine and offers a two-rak'at prayer during which he does not think of
anything else (not related to the present prayer) then his past sins will be
forgiven.' " After performing the ablution 'Uthman said, "I am going
to tell you a Hadith which I would not have told you, had I not been compelled
by a certain Holy Verse (the sub narrator 'Urwa said: This verse is:
"Verily, those who conceal the clear signs and the guidance which we have
sent down...)" (2:159). I heard the Prophet saying, 'If a man performs
ablution perfectly and then offers the compulsory congregational prayer, Allah
will forgive his sins committed between that (prayer) and the (next) prayer
till he offers it. (Bukhari Book #4,
Hadith #161).

Difference between Adhan & Iqama:

Narrated Anas: The people mentioned the fire and the bell
(they suggested those as signals to indicate the starting of prayers), and by
that they mentioned the Jews and the Christians. Then Bilal was ordered to
pronounce adhan for the prayer by saying its wordings twice, and for the Iqama
(the call for the actual standing for the prayers in rows) by saying its
wordings once. (Iqama is pronounced when the people are ready for the prayer).
(Bukhari Book #11,
Hadith #577).

Narrated Anas: Bilal was ordered to repeat the wording of
the adhan for prayers twice, and to pronounce the wording of the Iqamas once
except "Qad-qamat-is-Salat". (Bukhari Book
#11,
Hadith #579).

Use of sutra (prayer block) to walk
or cross in front of a praying person:

Narrated Abu Salih As-Samman: I saw Abu Said Al-Khudri
praying on a Friday, behind something which acted as a sutra. A young man from Bani
Abi Mu'ait, wanted to pass in front of him, but Abu Said repulsed him with a
push on his chest. Finding no alternative he again tried to pass but Abu Said
pushed him with a greater force. The young man abused Abu Said and went to Marwan
and lodged a complaint against Abu Said and Abu Said followed the young man to Marwan
who asked him, "O Abu Said! What has happened between you and the son of
your brother?" Abu Sa'id said to him, "I heard the Prophet saying,
'If anybody amongst you is praying behind something as a sutra and somebody
tries to pass in front of him, then he should repulse him and if he refuses, he
should use force against him for he is a satan.' " (Bukhari Book #9,
Hadith #488).

Narrated Ibn 'Umar: Whenever Allah's Apostle came out on 'Id
day, he used to order that a Harba (a short spear) to be planted in front of
him (as a sutra for his prayer) and then he used to pray facing it with the
people behind him and used to do the same while on a journey. After the Prophet
, this practice was adopted by the Muslim rulers (who followed his traditions).
(Bukhari Book #9,
Hadith #473).

Narrated Nafi: "I saw Ibn 'Umar praying while taking
his camel as a sutra in front of him and he said, "I saw the Prophet doing
the same." (Bukhari Book #8,
Hadith #422).

Narrated 'Abdullah: The Prophet used to get a Harba planted
in front of him (as a sutra) and pray behind it. (Bukhari
Book #9,
Hadith #477).

Narrated Abu Juhaifa: Allah's Apostle came out at midday and offered a two-Rak'at Zuhr and 'Asr prayers at Al-Batha and an 'Anza was planted
in front of him (as a sutra). He performed ablution and the people took the
remaining water left after his ablution and rubbed their bodies with it. (Bukhari Book #9,
Hadith #480).

Narrated Ibn Umar: On the day of 'Id-ul-Fitr and 'Id-ul-Adha
a spear used to be planted in front of the Prophet I (as a sutra for the
prayer) and then he would pray. (Bukhari Book #15,
Hadith #89).

Dhikir or zikr was part of the
prayer during the time of the Prophet (S):

Narrated Abu Ma'bad: (the freed slave of Ibn 'Abbas) Ibn 'Abbas
told me, "In the lifetime of the Prophet it was the custom to celebrate
Allah's praises aloud after the compulsory congregational prayers." Ibn 'Abbas
further said, "When I heard the Dhikr, I would learn that the compulsory
congregational prayer had ended." (Bukhari
Book #12,
Hadith #802).

Narrated Abu Ma'bad: (the freed slave of Ibn 'Abbas) Ibn 'Abbas
told me, "In the lifetime of the Prophet it was the custom to celebrate
Allah's praises aloud after the compulsory congregational prayers." Ibn 'Abbas
further said, "When I heard the Dhikr, I would learn that the compulsory congregational
prayer had ended." (Bukhari Book #12,
Hadith #802).

Prophet’s (S) dua after the prayer:

Narrated Warrad: (the clerk of Al-Mughira bin Shu'ba) Once
Al-Mughira dictated to me in a letter addressed to Mu'awiya that the Prophet
used to say after every compulsory prayer, "La ilaha ilallah wahdahu la sharika
lahu, lahul-mulku wa-lahul-hamdu, wahuwa ala kulli shai in qadir. Allahumma la mani
'a lima a'taita, wa la mu'tiya lima mana'ta, wa la yanfa'u dhal-jaddi minka-l-jadd.
(None has the right to be worshipped but Allah and He has no partner in
Lordship or in worship or in the Names and the Qualities, and for Him is the
Kingdom and all the praises are for Him and He is omnipotent. O Allah! Nobody
can hold back what you give and nobody can give what You hold back. Hard
(efforts by anyone for anything cannot benefit one against Your Will)."
And Al-Hasan said, "Al-jadd' means prosperity." (Bukhari Book #12,
Hadith #805).

Sunnat and nafl prayers are to be
prayed at home:

Narrated Zaid bin Thabit: Allah's Apostle made a small room
in the month of Ramadan (Sa'id said, "I think that Zaid bin Thabit said
that it was made of a mat") and he prayed there for a few nights, and so
some of his companions prayed behind him. When he came to know about it, he
kept on sitting. In the morning, he went out to them and said, "I have
seen and understood what you did. You should pray in your houses, for the best prayer
of a person is that which he prays in his house except the compulsory prayers." (Bukhari Book #11,
Hadith #698).

Narrated 'Aisha: Allah's Apostle used to pray eleven Rakat
at night and that was his night prayer and each of his prostrations lasted for
a period enough for one of you to recite fifty verses before Allah's Apostle
raised his head. He also used to pray two Rakat (Sunna) before the (compulsory)
Fajr prayer and then lie down on his right side till the Muadh-dhin came to him
for the prayer. (Bukhari Book #16,
Hadith #108).

Narrated Ibn 'Umar: The Prophet had said, "Offer some
of your prayers (Nawafil) at home, and do not take your houses as graves."
(Bukhari Book #8,
Hadith #424).

Witr or Bitr prayer (One or three rakats):

Narrated 'Abdullah bin 'Umar : The Prophet said, "Night
prayer is offered as two Rakat followed by two Rakat and so on, and if you want
to finish it, pray only one Raka which will be witr for all the previous Rakat."
Al-Qasim said, "Since we attained the age of puberty we have seen some
people offering a three-Rakat prayer as witr and all that is permissible. I
hope there will be no harm in it." (Bukhari
Book #16,
Hadith #107).

Narrated 'Aisha: Allah's Apostle offered witr prayer at
different nights at various hours extending (from the 'Isha' prayer) up to the
last hour of the night. (Bukhari Book #16,
Hadith #110).

Narrated 'Aisha, The Prophet (p.b.u.h) used to offer
thirteen Rakat of the night prayer and that included the witr and two Rakat (Sunna)
of the Fajr prayer. (Bukhari Book #21,
Hadith #241).

Tarawih prayer is to be offered at home during Ramadan:

Narrated Zaid bin Thabit: Allah's Apostle made a small room
(with a palm leaf mat). Allah's Apostle came out (of his house) and prayed in
it. Some men came and joined him in his prayer. Then again the next night they
came for the prayer, but Allah's Apostle delayed and did not come out to them.
So they raised their voices and knocked the door with small stones (to draw his
attention). He came out to them in a state of anger, saying, "You are
still insisting (on your deed, i.e. tarawih prayer in the mosque) that I
thought that this prayer (tarawih) might become obligatory on you. So you
people, offer this prayer at your homes, for the best prayer of a person is the
one which he offers at home, except the compulsory (congregational)
prayer." (Bukhari Book #73,
Hadith #134).